In the last decade, intensive pharmacological research concerning .gamma.-aminobutyric acid (hereinafter designated GABA), a neurotransmitter in the central nervous system, has taken place.
Increased GABA'ergic activity is useful in the treatment of anxiety, pain, epilepsy and muscular and movement disorders. Furthermore, these compounds can be used as sedatives.
In U.S. Pat. No. 4,383,999 (Smithkline Beckmann Corporation) some derivatives of N-(4-phenyl-3-butenyl)-azaheterocyclic carboxylic acids which have furthermore, inter alia phenyl, p-fluorophenyl, cyclohexyl or thienyl in the 4-position, are described.
According to J.Pharm.Exp.Therap. 228 (1984), 109 et seq., N(4,4-diphenyl-3-butenyl)nipicotic acid (designated SK&F 89976A), N-(4,4-diphenyl-3-butenyl)guvacine (designated SK&F 100330A), N-(4,4-diphenyl-3-butenyl)-.beta.-homoproline (designated SK&F 10056) and N-(4-sphenyl-4-(2-thienyl)-3-butenyl)nipecotic acid (designated SK&F 100604J) are orally active inhibitors of GABA uptake.
It is further well recognized in the art that .beta.-homoproline, nipecotic acid and guvacine are biological equivalents, at least as far as their GABA-like effects regards. See for example Progress in Medicinal Chemistry 21, 67-120 (1985); ed. Ellis West; Elsevier Science Publishers; Molecular and Cellular Biochemistry 31, 105-121 (1980), and J. Pharm.Exp.Therap., 228 (1984), 109 et seq. In practice of this invention they have been found to be biological equivalents.